Neuroimaging: MRI Basics for Neurologists
T1, T2, FLAIR, and DWI sequence interpretation for acute and chronic pathology.
Core Sequences
| Sequence | Utility / Appearance |
|---|---|
| T1-Weighted | Anatomy. Gray matter is gray, white matter is white, CSF is dark. Contrast (Gadolinium) highlights breakdown of the blood-brain barrier. |
| T2-Weighted | Pathology. CSF is bright. Most lesions (edema, ischemia, demyelination) appear bright (hyperintense). |
| FLAIR | T2 with CSF signal suppressed. Excellent for identifying periventricular lesions (e.g., MS plaques). |
| DWI / ADC | Diffusion Weighted Imaging. Highly sensitive for acute ischemia (cytotoxic edema restricts diffusion, appearing bright on DWI and dark on ADC map). |
Common Clinical Mistakes
- Premature anchoring on common diagnoses without evaluating red flags.
- Over-reliance on neuroimaging while neglecting detailed physical exams.
- Suboptimal dosing of first-line agents before declaring treatment failure.
Frequently Asked Questions
- When is immediate specialist referral required?
- Urgent referral is indicated for sudden onset of severe symptoms, rapidly progressive deficits, or when standard therapies fail.
- What are the primary outcome measures in recent clinical trials?
- Most contemporary trials focus on slowing disease progression (e.g., EDSS in MS, UPDRS in Parkinson's) and reducing relapse/event rates.
- How does this condition impact patient life expectancy?
- While highly variable, modern disease-modifying therapies have significantly improved long-term survival rates across neurodegenerative and neuroimmunological disorders.